Anembryonic pregnancy: what is it and why does it occur?

Anembryonic or anembryonic gestation is also called hollow egg. It is a specific type of abortion. What happens is that an egg is fertilized by a sperm and implants itself in the uterus. However, no embryo develops.

Anembryonic pregnancy is a common problem. Although in most cases subsequent pregnancies usually happen without any problem, it can have a great impact on the woman who suffers it. Therefore, in this article we explain everything you need to know about anembryonic pregnancy and why it occurs.

What is anembryonic gestation?

Anembryonic gestation, as we have indicated, It is one in which no embryo develops. Although the egg is implanted and the gestational sac develops, it is empty. It is a specific type of abortion, since with the passage of time there is a spontaneous exit of the content and the embryo sac is expelled.

Anembryonic gestation takes place early in pregnancy. That is, it is during the first weeks when development stops or it is diagnosed that there is none. As explained by specialists in assisted reproduction, almost 50% of pregnancy losses during the first trimester are due to this situation.

Many women even experience an anembryonic pregnancy and miscarry before even knowing they were pregnant. What happens is that, although the tissues that would give rise to the embryo do not develop, the cells of the gestational sac continue to grow.

It is these cells that secrete a hormone called human chorionic gonadotropin. This substance is what produces the typical symptoms of the first trimester of pregnancy. It is also the one used to detect pregnancy with typical urine tests.

Therefore, the pregnancy test is usually positive and there are symptoms, even if it is not a viable pregnancy. In many cases, spontaneous abortion occurs early. However, other patients undergo specific treatments for expulsion to occur.

The pregnancy test is positive in these cases, even with the absence of a complete zygote, due to hormones.

What symptoms does it present?

As we have just mentioned, the human chorionic gonadotropin hormone is the one that, by increasing its concentration in the blood, produces the typical symptoms of the first trimester of pregnancy.

Most often there is nausea and vomiting. There is also often breast tenderness, fatigue and mood swings. Similarly, there is no menstrual bleeding.

However, in anembryonic gestation there is a point at which the yolk sac stops growing. The production of this hormone stops and the symptoms disappear. When the abortion is started, it is usual that slight vaginal bleeding and abdominal cramps appear.

We must not forget that, as with other types of abortion, anembryonic pregnancy can have a strong impact on the mother's mood. That is why it is important that there is sufficient moral support.

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Causes of anembryonic pregnancy

We have seen that anembryonic gestation occurs because the embryo does not develop. In a normal pregnancy, after fertilization, cells begin to divide. From different cell groups develop, on the one hand the embryo, and on the other the gestational sac that will give rise to the placenta.

The exact cause of the embryo not developing is not known. According to the Instituto Bernabeu, most cases are caused by a genetic abnormality. That is, due to some problem at the chromosomal level.

A study published in Genetics and Molecular Research explains that abnormalities on chromosome 9 are a common origin. Especially in the case of repeat abortions. On the other hand, an investigation carried out in Buenos Aires affirms that one of the factors that was repeated in women with anembryonic pregnancies were toxic agents. For example, tobacco and alcohol.

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How is it diagnosed?

The diagnosis of anembryonic pregnancy is usually made by ultrasound. Specifically, with transvaginal ultrasound. It is the one in which the transducer is inserted through the vagina. It allows you to see the uterus and its contents with greater precision.

In any pregnancy, the usual thing is that the embryo is appreciated from 6 weeks of gestation. What happens in these cases is that, when performing the ultrasound, the gestational sac is observed, but not the embryo.

If there are doubts about it, the ultrasound is repeated between 7 and 10 days later. If an embryo is still not seen, it is most likely an anembryonic gestation.

Treatments available for anembryonic pregnancy

There is no way to prevent or treat anembryonal pregnancy. At least, there is no treatment that can save the pregnancy. However, there are different ways to help a woman expel the remains.

Many patients prefer to wait for the abortion to occur spontaneously. However, if you choose to do it artificially, it can be done in different ways. One of them is taking medications, such as misoprostol.

Another option is surgical treatment. It consists of performing a curettage to remove the tissues of the uterus. The approach should be chosen based on the health and condition of the woman. It may be advisable if the news has had a great impact for her and it is preferred to end the situation as soon as possible.

When to see a doctor

Ideally, any woman suspected of being pregnant should see a doctor. Certain initial checks must be followed. The first ultrasound is usually performed in the first 12 weeks of gestation.

However, if a pregnant woman has symptoms such as unexplained bleeding or abdominal discomfort, she should go urgently. Especially if there is a history of previous abortions.

Ultrasound allows detecting an anembryonic egg in time to take the corresponding measures.

Possible complications of anembryonic pregnancy

Anembryonic pregnancy does not usually lead to complications. It can influence the illusion or the mood of the mother or the family. Similarly, it causes fear of a second pregnancy.

However, most women have no problem with subsequent pregnancies. Ideally, allow about two or three normal menstrual cycles if you want to get pregnant again.

Having had an anembryonic pregnancy does not mean that all pregnancies will be like this. But it is true that there may be factors that it is advisable to study. Especially if there is more than one abortion in that woman.

In these cases, an analysis of the semen and the ovules can be performed. Also a preimplantation genetic screening to see if there are any genetic abnormalities. In addition, it is recommended that before trying to have another pregnancy, toxic habits are eliminated, if any, and diet is improved.

Anembryonic gestation does not determine other pregnancies

An anembryonic pregnancy is one in which the gestational sac develops, but not the embryo. The exact cause is not known. However, it is believed that much of the cases are due to chromosomal abnormalities. The mother's toxic habits can also play a role.

Anembryonic gestation culminates in abortion. There is no treatment to avoid or prevent this situation. Still, there are approaches that can expedite the tissue expulsion process.

It is important to re-emphasize the fact that Suffering from this problem does not mean that subsequent pregnancies will end in the same way. Therefore, it is always essential to consult any questions with a doctor. In addition, if there is any kind of discomfort or suspicion, you also have to go to the specialist.